Optical recording medium

Abstract

An optical recording medium is disclosed, which has a substrate and a recording film formed on the substrate. The recording film has a film comprising tin as the main component and passive state-forming metal layers formed on both sides of the tin film. The optical recording medium has a high recording sensitivity, a good signal quality and a high reliability. The optical recording medium is prepared by forming a first passive state-forming metal layer, a film comprising tin as the main component and a second passive state-forming metal layer in sequence on a substrate, and preferably heating the thus-obtained laminate.

We claim: 
     
       1. An optical recording medium comprising a substrate and a recording film formed on the substrate, said recording film having a film comprising tin as the main component and passivate state metal oxide layers formed on both sides of the tin film, each passive state metal oxide layer having a thickness of 5 to 40 angstroms. 
     
     
       2. An optical recording medium as set forth in claim 1, wherein the film comprising tin as the main component is composed of stannous sulfide or stannous selenide. 
     
     
       3. An optical recording medium as set forth in claim 1, wherein the film comprising tin as the main component is formed by dispersing fine particles of tin in at least one member selected from the group consisting of oxides, sulfides and selenides of tin. 
     
     
       4. An optical recording medium as set forth in claim 1, wherein the film comprising tin as the main component is composed of a tin selenide represented by the formula of Sn x  Se 100-x  in which x is a number of from 40 to 70. 
     
     
       5. An optical recording medium as set forth in claim 1, wherein the thickness of the film comprising tin as the main component is 50 to 300 angstroms. 
     
     
       6. An optical recording medium as set forth in claim 1, wherein the passive state metal oxide layers are formed from a passive state-forming metal selected from the group consisting of Al, Ti, Cr, Co, Ni, Nb, Ta and Zr. 
     
     
       7. An optical recording medium as set forth in claim 1, wherein the passive state metal oxide layers are formed from Ti or Cr. 
     
     
       8. An optical recording medium as set forth in claim 4, wherein the passive state metal oxide layers are formed from Ti.